Energy-Efficient NOMA with QoS-Guaranteed Power Allocation for Multi-User VLC

In this paper, we propose an energy-efficient nonorthogonal multiple access (NOMA) technique for multi-user visible light communication (VLC) systems, by adopting a low-complexity quality of service (QoS)-guaranteed power allocation strategy. From the perspective of energy saving, we design the energy-efficient NOMA-enabled multi-user VLC system with the goal to achieve maximal energy efficiency (EE). The closed-form QoS-guaranteed optimal power allocation strategy is obtained and the analytical EE of the proposed NOMA-enabled multiuser VLC system is derived. The analytical and simulation results show that, for a VLC system with ten users, the average EE can be improved by 19% when adopting the proposed NOMA in comparison to NOMA with gain ratio power allocation (GRPA), and the EE improvement becomes much more significant when the users have more diverse QoS requirements.